TABLE 2.

Main immune cells in heart failure.

Immune cells	Functions	Potential therapeutic targets from animal studies
Macrophages	Elevated CCR2+MHCIIhighLy6c+ macrophages in myocardium could secrete inflammatory cytokines and contribute to ventricular dysfunction	CCR2–CCL2 signaling axis
Mast cells	Attenuate left ventricular remodeling and promote cardiac dysfunction	Mast cell depletion
Neutrophils	Destructive at acute stage and protective at chronic stage	Annexin A1
Natural killer cells	Release cytokines and modulate immune system
Dendritic cells	Protective at acute stage and destructive at chronic stage
CD4+ T cells	TH1 cells are mainly proinflammatory
	TH2 cells are mainly profibrosis
	TH17 cells contribute to cardiac hypertrophy and promote adverse cardiac remodeling
B cells	Induce direct myocardial injury, produce inflammatory cytokines, and antibodies	B-cell depletion